heart block – the heart beats more slowly than normal and can cause people to collapse

ventricular fibrillation – a rare, rapid and disorganised rhythm of heartbeats that rapidly leads to loss of consciousness and sudden death if not treated immediately

Arrhythmias can affect all age groups, but atrial fibrillation is more common in older people. Drinking alcohol in excess or being overweight increases your likelihood of developing atrial fibrillation.

You may also be at risk of developing an arrhythmia if your heart tissue is damaged because of an illness – for example, if you have had a heart attack or have heart failure.

Atrial fibrillation is a common cause of stroke. Having atrial fibrillation means your risk of stroke is 5 times higher than for someone whose heart rhythm is normal.

Certain types of arrhythmia occur in people with severe heart conditions, and can cause sudden cardiac death. This kills 100,000 people in the UK every year. Some of these deaths could be avoided if the arrhythmias were diagnosed earlier.

Could you have an arrhythmia?

Arrhythmia Alliance's heart rhythm checklist can help you gather information to discuss with your GP if you have any of these symptoms.

Diagnosing arrhythmias

If your symptoms persist or there's a history of unexplained sudden death in your family, it's important for your GP to refer you to a heart specialist (a cardiologist or electrophysiologist who specialises in heart rhythm disorders).

The most effective way to diagnose an arrhythmia is with an electrical recording of your heart rhythm called an electrocardiogram (ECG). If the ECG doesn't find a problem, you may need further monitoring of your heart.

This may involve wearing a small portable ECG recording device for 24 hours or longer. This is called a Holter monitor or ambulatory ECG monitoring.

If your symptoms seem to be triggered by exercise, an exercise ECG may be needed to record your heart rhythm while you are using a treadmill or exercise bike.

You should request a copy of your ECG. Take it with you to see the cardiologist or heart rhythm specialist and always keep a copy for future use.

Other tests used in diagnosing arrhythmias include:

cardiac event recorder – a device to record occasional symptoms over a period of time whenever you have them

electrophysiological (EP) study – a test to locate problems with the electrical signals in your heart by passing soft wires up a vein in your leg and into your heart while you are sedated

Treatment for arrhythmias

How your arrhythmia will be treated will depend on whether it is a fast or slow arrhythmia or heart block. Any underlying causes of your arrhythmia, such as heart failure, will need to be treated as well.

The treatments used for arrhythmias include:

medication – to stop or prevent an arrhythmia or control the rate of an arrhythmia

cardioversion – a treatment that uses electricity to shock the heart back into a normal rhythm while you are anaesthetised or sedated

catheter ablation – a keyhole treatment under local or general anaesthetic that carefully destroys the diseased tissue in your heart that causes the arrhythmia

pacemaker – a small device containing its own battery that is implanted in your chest under local anaesthetic; it produces electrical signals to do the work of the natural pacemaker in your heart to help it beat at a normal rate

ICD – a device similar to a pacemaker that monitors your heart rhythm and shocks your heart back into a normal rhythm whenever this is needed

Staying safe with an arrhythmia

If your job involves working at height or with machinery that could be dangerous, you will need to stop work at least until your arrhythmia is diagnosed or you get treatment for your underlying condition. Get advice from your GP or cardiologist.